use strict;
use warnings;
-use Carp 'confess';
-use Scalar::Util 'blessed', 'reftype', 'weaken';
+use Scalar::Util 'weaken', 'blessed';
-our $VERSION = '0.01';
+our $VERSION = '0.02';
sub meta {
require Class::MOP::Class;
# assumption,.. but you can
# never tell <:)
meta => $meta,
- slots => \@slots,
+ slots => { map { $_ => undef } @slots },
} => $class;
}
bless $instance_structure, $self->{meta}->name;
}
+sub clone_instance {
+ my ($self, $instance) = @_;
+ $self->bless_instance_structure({ %$instance });
+}
+
# operations on meta instance
sub get_all_slots {
my $self = shift;
- return @{$self->{slots}};
+ return keys %{$self->{slots}};
+}
+
+sub is_valid_slot {
+ my ($self, $slot_name) = @_;
+ exists $self->{slots}->{$slot_name} ? 1 : 0;
}
# operations on created instances
sub initialize_slot {
my ($self, $instance, $slot_name) = @_;
- $instance->{$slot_name} = undef;
+ $self->set_slot_value($instance, $slot_name, undef);
+}
+
+sub initialize_all_slots {
+ my ($self, $instance) = @_;
+ foreach my $slot_name ($self->get_all_slots) {
+ $self->initialize_slot($instance, $slot_name);
+ }
}
sub is_slot_initialized {
exists $instance->{$slot_name} ? 1 : 0;
}
+sub weaken_slot_value {
+ my ($self, $instance, $slot_name) = @_;
+ weaken $instance->{$slot_name};
+}
+
+sub strengthen_slot_value {
+ my ($self, $instance, $slot_name) = @_;
+ $self->set_slot_value($instance, $slot_name, $self->get_slot_value($instance, $slot_name));
+}
+
# inlinable operation snippets
+sub is_inlinable { 1 }
+
+sub inline_create_instance {
+ my ($self, $class_variable) = @_;
+ 'bless {} => ' . $class_variable;
+}
+
+sub inline_slot_access {
+ my ($self, $instance, $slot_name) = @_;
+ sprintf "%s->{%s}", $instance, $slot_name;
+}
+
sub inline_get_slot_value {
- my ($self, $instance_var_name, $slot_name) = @_;
- return ($instance_var_name . '->{\'' . $slot_name . '\'}');
+ my ($self, $instance, $slot_name) = @_;
+ $self->inline_slot_access($instance, $slot_name);
}
sub inline_set_slot_value {
- my ($self, $instance_var_name, $slot_name, $value_name) = @_;
- return ($self->inline_get_slot_value($instance_var_name, $slot_name) . ' = ' . $value_name);
+ my ($self, $instance, $slot_name, $value) = @_;
+ $self->inline_slot_access($instance, $slot_name) . " = $value",
}
sub inline_initialize_slot {
- my ($self, $instance_var_name, $slot_name) = @_;
- $self->inline_set_slot_value($instance_var_name, $slot_name, 'undef');
+ my ($self, $instance, $slot_name) = @_;
+ $self->inline_set_slot_value($instance, $slot_name, 'undef'),
}
sub inline_is_slot_initialized {
- my ($self, $instance_var_name, $slot_name) = @_;
- return ('exists ' . $self->inline_get_slot_value($instance_var_name, $slot_name) . ' ? 1 : 0');
+ my ($self, $instance, $slot_name) = @_;
+ "exists " . $self->inline_slot_access($instance, $slot_name) . " ? 1 : 0";
+}
+
+sub inline_weaken_slot_value {
+ my ($self, $instance, $slot_name) = @_;
+ sprintf "Scalar::Util::weaken( %s )", $self->inline_slot_access($instance, $slot_name);
+}
+
+sub inline_strengthen_slot_value {
+ my ($self, $instance, $slot_name) = @_;
+ $self->inline_set_slot_value($instance, $slot_name, $self->inline_slot_access($instance, $slot_name));
}
1;
=head1 SYNOPSIS
+ # for the most part, this protocol is internal
+ # and not for public usage, but this how one
+ # might use it
+
+ package Foo;
+
+ use strict;
+ use warnings;
+ use metaclass (
+ ':instance_metaclass' => 'ArrayBasedStorage::Instance',
+ );
+
+ # now Foo->new produces blessed ARRAY ref based objects
+
=head1 DESCRIPTION
+This is a sub-protocol which governs instance creation
+and access to the slots of the instance structure.
+
+This may seem like over-abstraction, but by abstracting
+this process into a sub-protocol we make it possible to
+easily switch the details of how an object's instance is
+stored with minimal impact. In most cases just subclassing
+this class will be all you need to do (see the examples;
+F<examples/ArrayBasedStorage.pod> and
+F<examples/InsideOutClass.pod> for details).
+
=head1 METHODS
=over 4
-=item B<new>
+=item B<new ($meta, @attrs)>
+
+Creates a new instance meta-object and gathers all the slots from
+the list of C<@attrs> given.
+
+=item B<meta>
+
+This will return a B<Class::MOP::Class> instance which is related
+to this class.
+
+=back
-=item B<bless_instance_structure>
+=head2 Creation of Instances
-=item B<compute_layout_from_class>
+=over 4
=item B<create_instance>
+This creates the appropriate structure needed for the instance and
+then calls C<bless_instance_structure> to bless it into the class.
+
+=item B<bless_instance_structure ($instance_structure)>
+
+This does just exactly what it says it does.
+
+=item B<clone_instance ($instance_structure)>
+
+=back
+
+=head2 Instrospection
+
+NOTE: There might be more methods added to this part of the API,
+we will add then when we need them basically.
+
+=over 4
+
=item B<get_all_slots>
-=item B<get_slot_value>
+This will return the current list of slots based on what was
+given to this object in C<new>.
-=item B<set_slot_value>
+=item B<is_valid_slot ($slot_name)>
-=item B<initialize_slot>
+=back
+
+=head2 Operations on Instance Structures
+
+An important distinction of this sub-protocol is that the
+instance meta-object is a different entity from the actual
+instance it creates. For this reason, any actions on slots
+require that the C<$instance_structure> is passed into them.
+
+=over 4
-=item B<is_slot_initialized>
+=item B<get_slot_value ($instance_structure, $slot_name)>
-=item B<inline_get_slot_value>
+=item B<set_slot_value ($instance_structure, $slot_name, $value)>
-=item B<inline_set_slot_value>
+=item B<initialize_slot ($instance_structure, $slot_name)>
-=item B<inline_initialize_slot>
+=item B<initialize_all_slots ($instance_structure)>
-=item B<inline_is_slot_initialized>
+=item B<is_slot_initialized ($instance_structure, $slot_name)>
+
+=item B<weaken_slot_value ($instance_structure, $slot_name)>
+
+=item B<strengthen_slot_value ($instance_structure, $slot_name)>
=back
-=head2 Introspection
+=head2 Inlineable Instance Operations
+
+This part of the API is currently un-used. It is there for use
+in future experiments in class finailization mostly. Best to
+ignore this for now.
=over 4
-=item B<meta>
+=item B<is_inlinable>
-This will return a B<Class::MOP::Class> instance which is related
-to this class.
+Each meta-instance should override this method to tell Class::MOP if it's
+possible to inline the slot access.
+
+This is currently only used by Class::MOP::Class::Immutable when performing
+optimizations.
+
+=item B<inline_create_instance>
+
+=item B<inline_slot_access ($instance_structure, $slot_name)>
+
+=item B<inline_get_slot_value ($instance_structure, $slot_name)>
+
+=item B<inline_set_slot_value ($instance_structure, $slot_name, $value)>
+
+=item B<inline_initialize_slot ($instance_structure, $slot_name)>
+
+=item B<inline_is_slot_initialized ($instance_structure, $slot_name)>
+
+=item B<inline_weaken_slot_value ($instance_structure, $slot_name)>
+
+=item B<inline_strengthen_slot_value ($instance_structure, $slot_name)>
=back
-=head1 AUTHOR
+=head1 AUTHORS
+
+Yuval Kogman E<lt>nothingmuch@woobling.comE<gt>
Stevan Little E<lt>stevan@iinteractive.comE<gt>
it under the same terms as Perl itself.
=cut
+
projects / gitmo/Class-MOP.git / blobdiff